Event sponsors can now be managed and displayed as part of the Online Event app without requiring track management. Sponsor-related online and chat features are moved into the exhibitor area, making sponsorship setup simpler and more focused for event organizers.

…ne event

The Documents app test setup now uses shared test assets in a more consistent way. This is an internal quality improvement that helps keep automated tests easier to maintain without changing how users work with documents.

task-2411138

Deletion safeguards were moved to a safer standard mechanism across several Odoo apps. This helps keep business rules consistent when records are removed, reducing the risk of accidental data issues without changing day-to-day workflows.

With this commit, all instances of errors being raised inside
`BaseModel.unlink` overrides are moved into methods decorated with
`api.ondelete` which is safer.

Linked to https://github.com/odoo/odoo/pull/58517